Alberto Contador, who spent the first two weeks of this year's Vuelta attempting to drop Joaquin Rodriguez whenever the road headed uphill, today put in a stunning ride on the flat to win Stage 17 and take over the lead of the race as it heads into its closing days. The Saxo Bank-Tinkoff Bank rider had already distanced Rodriguez when he put in a storming attack from the lead group alongside former team mate Paolo Tiralongo of Astana, then rode the final 13 kilometres alone to finish a few seconds ahead of Movistar's Alejandro Valverde, who moves to second overall.

Rodriguez, who lost the Giro d'Italia in May on the final day after spending ten days of that race in the maglia rosa, has spent even longer in the Vuelta's leader's jersey this year, but will almost certainly miss out once again on a maiden Grand Tour victory, losing more than two and a half minutes to Contador today.

The 2012 Vuelta was already destined to be a memorable race as a result of some thrilling battles over the past fortnight, but today's stage was simply sensational. Should Contador go on to take his second Vuelta, adding to his 2008 victory, this will be remembered as the day he won it. Should Rodriguez end his career without a Grand Tour win, it will be viewed as the day - perhaps alongside the time trial that concluded the Giro in Milan - when he let his best chance slip.

While today's stage featured a summit finish, the Category 2 ascent to Fuente Dé was viewed as much less taxing than those that had featured in the three stages preceding yesterday's rest day, but the damage to Rodriguez's GC hopes had already been done prior to that climb starting.

In last year's Giro d'Italia, Contador gifted Tiralongo his first ever professional victory when the pair found themselves alone on the Stage 19 climb of the Macugnaga.

Tiralongo would subsequently testify on behalf of his friend and former Astana team mate at the Court of Arbitration for Sport hearing that resulted in the Spaniard being banned for six months earlier this year for his positive test for clenbuterol in the 2010 Tour de France.

Tiralongo continued to stand by Contador, dedicating his Giro stage victory at Rocca di Cambio in this year's race to him, but if he still owed him a debt for that 2011 stage win, it was repaid in full this afternoon as the pair set team rivalries aside and went hell for leather, attacking from the leading group with around 20km of today's stage left to ride.

Rodriguez had been distanced by Contador 30km earlier when the latter slipped into that front group, but if it was the Saxo Bank rider's move that had put the race leader into difficulties, it was Valverde who delivered the coup de grace, his attack at around 12 kilometres out leaving the Katusha rider with no way back and what must have been a very lonely ride to the finish with two of Contador's team mates sitting on his wheel.

There is one more summit finish to come in the race, on the Bola del Mundo on Saturday, and it's one Contador knows better than anyone, close enough to his home outside Madrid for him to ride up it in the morning and be home in time for lunch.

Asked afterwards about how he had managed to seize control of the race, Contador confessed, "I’ve attacked instinctively. I believe this day of racing has shocked a few!

"Truly, I’ve ridden a bit like a kamikaze. But I had to try. I felt something like an angel and a devil on my shoulders. One was telling me: 'Attack,' the other one said: 'Don’t attack.' I followed the right advice. I’ve been scared to lose my advantage in the last fifteen kilometers because I hadn’t eaten a lot. I was afraid that other riders could catch me.

He admitted that physically, "I wasn’t on one of my best days. But my will to succeed was enormous. Second place isn’t bad but you always have to try and win, even though many people thought it was out of reach for me.

"My attack with 50 km to go was of an absolute madness. I told my three team-mates via radio to go “full gas”, and nothing more because sometimes the radios are pirated by other teams. And I’ve climbed with the same conviction I had up to l’Alpe d’Huez in the 2011 Tour de France.

He said that today's victory was "one of the three most important of my career. The first one was at the 2005 Tour Down Under when I resumed racing after my big accident. The second one was the 2007 Paris-Nice.

"It’s not finished yet but Joaquim Rodriguez must be congratulated for what he has done during this Vuelta. I wasn’t able to drop him off in the steepest uphill finishes, so every day I had to think of the tactic for the next day. I’ve had to calculate a lot the time not to lose and the right spot for attacking him."

"The stage to Fuente Dé will make history and I’m proud to be part of it. Contador has demonstrated to being the strongest and his team as well. When I’ve seen him climbing, the disaster that I was going to encounter didn’t cross my mind. We didn’t imagine what was going to happen, no one did.

"I’ve experienced different states of mind in the last fifty kilometres. From the Collado La Hoz, I just it would come well in the downhill with the help of riders from Movistar but it didn’t. Today, for sure, it’ll be hard for me to sleep!”

Contador said that before last year's Giro, and what he meant by it was that if you're not leading the race, you don't have to spent an hour or more after each stage doing presentations, press and TV when you could be back at the hotel getting massaged, fed and rested.

You can see why it gets quoted out of context mind

I think Rodriguez has spent 23 days now leading Grand Tours in 2012 and he's going to end up with nothing.

What really bugged me was the Saxobank rider, who sat on Rodriguez's wheel the whole time, celebrating his demise as he crossed the line, not so much that C. had won but that Rodriguez had been crushed, even allowing for the fact that Rodriguez had been a bit dozy. Astana, Contador, Valverde, Riis - umm, nice! Incidentally, what on earth is Nicholas Roche doing getting mixed up with that shower next season? Rant over!

Looking at the last few mountain stages you could be forgiven for looking at the Spanish riders and wondering a little where they get their pep from. I've never seen 3 GC riders of any nationality - let alone the same - tackle 20% hills at that speed before. It defies belief that all 3 are that good all at the same time.

I know nothing of the intricacies of how doping works but is it too simplistic to suggest that if a doper returns from a doping ban with equal or better form is safe to assume the status quo has been maintained?
Logic would suggest a drop off in form after a doping ban because , of course, one has learnt ones lesson and turned ones back on the evils of performance enhancing drugs and therefore performance will drop.
I am willing to be proved wrong and if i am - Chapeau! to Contador and Valverde for finding such excellent form and wish them all the best on their new, drug free, journey.

It's quite possible that all three leaders have or are currently doping. Certainly the Spanish don't have a great reputation, but then the French think the British all cheat, so it just depends on where you're looking from.

Professional sport is basically entertainment and you can't say the Vuelta hasn't been interesting. Plenty of cheating goes on in football at all levels but it doesn't stop me watching it. If anything it makes it more interesting. Did Owen dive in 98? Maybe. Did a few people have a little new blood on the rest day? Maybe. I'd like cycling to be clean and players not dive but it's probably never going to happen. Just enjoy the racing and don't turn athletes into heroes. They're not.

Former cheats will have residual benefit from the years where they were training with drugs. Such is the case in athletics with Chambers, Gatlin et al. So it is the case C 'n' V are not performing 'clean', at least not in the immediate future. No doubt over time this benefit will diminish. However, C 'n' V are too close to the period when they were convicted to be free of any benefit derived, even if not having 'medical support' at the moment.

Yes, Contador and Valdeverde ride away from the field having returned from their suspensions for doping/blood doping. Both are unrepentant cheats, so it fills one with enthusiasm for Spanish practices. I also felt that the display by Rodriguez was decidedly odd given that he had had stated before the stage that he must stay with Contador - in fact that is all he needed to do. The sight of the admitted drug cheat team manager Riis feeding bags and sustenance to all and sundry in the group which was supporting Contador turned my stomach.

This years Vuleta has been the best grand tour this year to watch, so regardless of what you think of Bertie and Valverde you cant deny its been exciting! and if your not watching it just because you dont like contador or agree with him racing then your missing out on a truly gripping race!
I've watched all of the Giro, all of the TdF and the Vuleta and this one is by far the most enjoyable! And it is usually my least favorite to watch!

I suppose this is the problem, really. TV audiences and big-money sponsorship deals are driven by big entertaining rides, grand victories akin to battling gladiators slugging it out for the spoils. Yet, in an endurance sport where a single event can last three weeks, how can athletes do anything more than eke out small time bonuses from stage wins, or gaps in time trials? There is a way, but are we turning a blind eye to it by appreciating this race as being more exciting than others?

In theory, there is no difference between theory and practice, but in practice...

Wow; I have not seen anyone do that since the Hinault days! What a stage! Just like Contador I had an angel and a devil on my shoulders; but my devil was saying, "Drugs". Hopefully we can move on from that shamefull episode in cycling history.

There must surely now be enough 'clean' teams to say - "Sod you lot - we will set up our own schedule and race against each other" whilst leaving the 'old skool' lot to skip up and down the mountains of Europe on pixie dust and magic moonbeams.
As has been noted elsewhere, the balance of power is shifting to the English speaking nations and if Sky, BMC, OGE and Garmin put their weight behind it im sure they could get a serious programme together. I dont how the UCI would figure in this 'plan' that i have just thought up but we can leave the details to others!

There must surely now be enough 'clean' teams to say - "Sod you lot - we will set up our own schedule and race against each other" whilst leaving the 'old skool' lot to skip up and down the mountains of Europe on pixie dust and magic moonbeams.

The problem is, which of those two sets of races would most people rather watch? The slow attritional 'Sky' tours, or the explosive, exciting, drug-fueled riots of the 'Spanish' tours?

Also, who gets the TdF, Giro and Vuelta? Without those races any new body or set of races set up is pointless.

I agree with a previous comment about Nicholas Roche - disappointed he's getting involved with Bjarne Riis - always amazes me how he's so 'respected' and 'central' in world cycling.

I like it when riders have a bad day and blow up like yesterday, that's what should happen on a GC.
I'm always sceptical of 'unbelievable' 'superhuman' performances, especially after 3 brutal, brutal mountain stages. It's all gone a bit Floyd Landis at the Vuelta?

Like a hollywood blockbuster,I'm enjoying it, but not necessarily believing every word.

Yes, Contador and Valdeverde ride away from the field having returned from their suspensions for doping/blood doping. Both are unrepentant cheats, so it fills one with enthusiasm for Spanish practices. I also felt that the display by Rodriguez was decidedly odd given that he had had stated before the stage that he must stay with Contador - in fact that is all he needed to do. The sight of the admitted drug cheat team manager Riis feeding bags and sustenance to all and sundry in the group which was supporting Contador turned my stomach.

I heard this on the Radio 4 a while back and it makes for interesting listening/reading, whether or not Bertie, Valverde and Purito are doping I don't know. But wow the Vuelta this year has been absolutely gripping stuff. This is in part i think due to the parcours and the brutality of the climbs. The top three are only going 6mph on the slopes at the end. I don't think that is a clear sign of being doped up to the eyelids!

I like it when riders have a bad day and blow up like yesterday, that's what should happen on a GC.
I'm always sceptical of 'unbelievable' 'superhuman' performances, especially after 3 brutal, brutal mountain stages. It's all gone a bit Floyd Landis at the Vuelta?

Like a hollywood blockbuster,I'm enjoying it, but not necessarily believing every word.

I dunno, I wonder whether that's merely that Bertie had his microdose the night before because he planned to attack, whereas J-Rod thought he wouldn't need it on the relatively flat stage...?! This could all be bollocks mind, especially if it's all done weeks before.

In theory, there is no difference between theory and practice, but in practice...